Guidewires are frequently used to advance intravascular devices to various locations within the body such as an artery or vein. Examples of therapeutic procedures employing such devices include percutaneous transluminal coronary angioplasty (PTCA), percutaneous extraction atherectomy, and stent placement. In a PTCA procedure, for example, a guidewire is percutaneously inserted into a patient's body, and then advanced to a target site where a stenosis or other occlusion is located. Once in place, an angioplasty catheter having an inflatable balloon is advanced along the guidewire and positioned across the site of the stenosis to be dilated. The inflatable balloon is then inflated, causing some embolic material to dislodge from the wall of the vessel and flow downstream.
To prevent the escape of embolic material dislodged during the therapeutic procedure, an embolic protection filter can be advanced to a location distal the target site and deployed to capture emboli present within the blood stream. These devices typically comprise a support structure coupled to a filter mesh or membrane that captures embolic material such as plaque and thrombus, while permitting the perfusion of blood through the vessel. The embolic protection filter may be configured to self-deploy within the vessel when actuated, and may be configured to radially collapse within a catheter or other delivery device to facilitate transport through the body.
During interventional vascular procedures such as angioplasty, atherectomy, thrombectomy and stenting, access to the lesion is often exacerbated due to the tortuous nature of the vasculature. To access the site of the lesion to be treated, the physician may advance an elongated wire such as a guidewire to a location within the vessel distal the lesion. Such guidewires are typically 0.014 inches in diameter, and vary in stiffness along their length. Since such guidewires often have a relatively small profile in comparison to other intravascular devices such as angioplasty catheters or stent delivery catheters, the ability to advance an intravascular device across the site of the lesion may be improved by using more conventional guidewires.